textproduct: Rapid City

KEY MESSAGES

- Cooler weather prevails with precipitation chances through Thursday.

- Near-freezing temperatures overnight tonight and Tuesday and Thursday nights.

- Breezy Thursday with warmer weather for the weekend.

DISCUSSION

(This Evening Through Monday) Issued at 1235 PM MDT Mon Oct 12 2026

Closed upper low is centered over southeastern OR with deep trough axis extending southward off southern CA coast. Water vapor imagery shows shortwave trough pushing north of the forecast area into ND with additional moisture and embedded vort maxes to our west along the eastern periphery of the low. A surface cold front stretches from southern MN through northeastern NE back into southwestern NE. Low clouds with mist/fog persist across the forecast area early this afternoon, although breaks in the clouds are becoming more numerous and expansive. Cold tonight with many areas falling into the mid to upper 30s.

The upper low is forecast to dig into the southwestern US with the trough axis shifting further east overnight tonight into Tuesday as broad upper level ascent overspreads the region. Light rain possible overnight tonight into Tuesday morning with ample cloud cover. Additional chances of light precipitation arrive early Wednesday through Thursday morning, with the best chances for widespread precipitation along the SD/NE border and southward.

Northern stream trough is forecast to drop out of Saskatchewan and Manitoba into the Upper Midwest early Thursday, swinging a strong cold front through the Northern Plains and Upper Midwest. A strong belt of 850-700 mb wind (~40-60 knots) will push into ND and central SD, sideswiping the forecast area. The strongest cold air advection will remain displaced east of the forecast area, where strongest winds can be expected. Deterministic NBM guidance continues to forecast 60+ mph wind gusts across portions of NW SD and the western SD plains Thursday afternoon. However, an ingredients-based approach coupled with ensemble guidance does not support winds this strong. The current forecast has Wind Advisory level winds (~45 mph) for portions of NW SD into the western SD plains Thursday afternoon and evening, although there is low confidence that this solution verifies; certainly, the High Wind (>60 mph) potential looks unlikely (probability < 15%).

Western ridging returns next weekend with above average temperatures forecast and dry conditions.

AVIATION

(For the 18Z TAFS Through 18Z Tuesday) Issued At 1128 AM MDT Mon Oct 12 2026

The widespread IFR to LIFR conditions have been trending upward over the last few hours.

Looking ahead to the rest of today, MVFR to low-end VFR conditions are expected for NW SD into NE WY through the day, higher conditions likely for SW SD into central SD.

Widespread MVFR to localized IFR conditions expected tonight due to low clouds but can't rule out low visibility issues in parts of NE WY and around the Black Hills.

For the winds, expect breezy NW winds through the afternoon behind the passing front, mainly across northeast WY and SW SD. Winds will diminish this evening with lighter winds overnight.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.